Meteorite impact craters as natural "probes" and "gauges" on planetary surfaces

陨石撞击坑是行星表面的天然“探针”和“测量仪”

• 批准号: RGPIN-2014-04215
• 负责人: Tornabene, Livio
• 金额: $ 2.11万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610901
• 关键词: Meteorite; impact; craters; natural; probes

Impact cratering is the most ubiquitous geologic process acting on solid planetary surfaces throughout the solar system and, thereby, played a significant role in the early formation, modification and in some cases the aqueous alteration of planetary crusts. Mounting evidence supports that impact cratering has not only physically modified the rocky surfaces of Earth and Mars, but may have also played a significant role in the evolution of early life and the concentration of mineral resources via the hydrothermal activity (i.e., heat-driven circulation of fluids). Impact craters are relatively consistent in morphology making them one of the most easily recognized features on planetary surfaces. Thereby, they are also useful as “probes” and “gauges” of the target properties, and geologic processes that modify planetary surfaces, respectively. Craters excavate, uplift and expose subsurface rocks that may not otherwise be exposed by other processes, and in some cases provide the only bedrock samples of the deep subsurface. Spectral remote sensing of theses features is often employed to identify these subsurface rocks on planetary bodies. However, there are various crater-related effects within these features that need to be better understood, in order to fully understand their effects on the rocks. Pristine crater morphology and morphometry (e.g., crater depth) can be used as a standard to understand target material properties and the effects and rates of subsequent modifying geologic processes. In addition, pristine craters offer us a glimpse of the relatively unmodified primary crater deposits, providing insights into the impact cratering process itself, and potentially paleo-environments on planetary bodies with atmospheres and target volatiles (e.g., water). The long-term goals of my research program are to, 1) improve our understanding of the impact cratering process as a geologic process, and 2) learn about the geological history of upper crust and surface of Mars through remote sensing studies of its most ubiquitous landform – impact craters. This program aims to achieve these goals via three testable hypotheses, each of which are divided into four objectives involving the analysis and interpretation of orbital spectral, visible, thermophysical and elevation data sets of the Martian surface. Although the emphasis is not specifically terrestrial-based, the processing, visualization, analysis and interpretation of these data sets are similar to those utilized by exploration geology, geophysics, environmental remote sensing, and even employed for the purposes of national defense. As such, Highly Qualified Personnel (HQP) involved in this research program will learn techniques that are directly applicable to these fields.

撞击坑是作用在整个太阳系固体行星表面上最普遍的地质过程，因此，在行星地壳的早期形成、改变以及在某些情况下的水蚀变化中发挥了重要作用，越来越多的证据表明撞击坑并未发生。仅在物理上改变了地球和火星的岩石表面，但也可能在早期生命的进化和通过热液活动（即热驱动的流体循环）浓缩矿物资源方面发挥了重要作用。撞击坑的形态相对一致，使其成为行星表面最容易识别的特征之一，因此，它们也可分别用作目标属性和改变行星表面的地质过程的“探针”和“测量仪”。挖掘、隆起和暴露其他过程可能不会暴露的地下岩石，并且在某些情况下提供了深层地下的唯一基岩样本，这些特征的光谱遥感通常用于识别行星上的这些地下岩石。然而，这些特征中存在各种与陨石坑相关的影响，需要更好地理解，以便充分了解它们对岩石的影响，原始陨石坑的形态和形态测量（例如陨石坑深度）可以用作标准。了解目标材料特性以及随后改变地质过程的影响和速率此外，原始陨石坑使我们能够一睹未经改变的原始陨石坑沉积物，从而深入了解撞击坑形成过程本身，并有可能。具有大气和目标挥发物（例如水）的行星体上的古环境。 我的研究计划的长期目标是，1）提高我们对撞击坑过程作为地质过程的理解，2）通过对火星上最普遍的地壳和表面的遥感研究，了解上地壳和火星表面的地质历史。该计划旨在通过三个可测试的假设来实现这些目标，每个假设分为四个目标，涉及火星表面的轨道光谱、可见光、热物理和高程数据集的分析和解释。 尽管重点不是专门针对陆地的，但这些数据集的处理、可视化、分析和解释与勘探地质学、地球物理学、环境遥感甚至国防目的所使用的数据集类似，参与该研究计划的高素质人员（HQP）将学习直接适用于这些领域的技术。